PSIP1 belongs to the hepatoma-derived growth factor (HDGF) family of proteins that contain a well conserved N-terminal amino acid sequence known as the HATH (homologous to amino terminus of HDGF) region.

DNA binding domains and nuclear localization signal of LEDGF: contribution of two helix-turn-helix (HTH)-like domains and a stretch of 58 amino acids of the N-terminal to the trans-activation potential of LEDGF.